Machining operations, such as milling or turning operations, are widely used to manufacture parts. Typically, a part is machined from a solid piece of material, such as a metal (e.g., aluminum, steel, etc.) billet. One problem often encountered when machining parts in this manner is due to residual stress in the material, which is generally caused by machining-induced residual stress as the result of local surface deformations caused by the cutting tool and/or by residual stress induced in material processing prior to machining, which are released during machining processes. Residual stress can cause distortion of the part, such as bowing, warping, and twisting, often resulting in the part being “out of tolerance” and unacceptable for use. This leads to scrapping the part or to reworking the part in an attempt to make the part acceptable. Such rework is often extensive and costly. Traditionally, machinists attempt to mitigate residual stress distortion by machining a part with successive roughing operations, with a time interval between roughing passes to allow residual stress distortion to occur, until a final part is achieved with a finishing pass or operation. Other approaches to solving the residual stress distortion problem involve altering the physical properties of the raw material or mechanically straightening parts after machining operations.
Reference will now be made to the exemplary embodiments illustrated, and specific language will be used herein to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended.